The proliferation of the wireless local area networks (WLANs) has led to the search for ways in which its utilization can be increased. By WLAN, we include all instantiations of such technologies as 802.11 a, 802.11 b, 802.11 g, Bluetooth and any similar WLAN versions. For example, the specification for the IEEE 802.11 version of WLAN includes an access scheme called the distributed control function, which permits the network to support both data and voice applications. Today voice over wireless local area network (VoWLAN) is a reality. The voice may be encoded and transmitted using voice over internet protocol (VoIP) format and protocols such as G.711, G.726, G.729, SIP, MEGACO, H.323, or other similar protocols that are being developed.
One of the issues in WLAN is that there is a limited range of operation due to power requirements. For example, a typical IEEE 802.11 WLAN has a range of at most 300 yards from the access point that connects the mobile devices to the wired LAN. Thus, when an IEEE 802.11-based mobile device roams beyond this range, any call in progress is forcibly terminated.